Housing Cleaning Device for Cleaning a Housing of a Screw Machine

The present application is a divisional of U.S. patent application Ser. No. 17/433,683 filed on Aug. 25, 2021, which is a U.S. National Stage Entry under 35 U.S.C. § 371 of International Application No. PCT/EP2020/055784, filed on Mar. 5, 2020, which claims the priority benefit of German Patent Application DE 10 2019 203 661.9 filed Mar. 19, 2019, the disclosures of which are hereby incorporated by reference in their entirety.

The invention relates to a housing cleaning device for cleaning a housing of a screw machine. The invention further relates to a shaft cleaning device for cleaning at least one treatment element shaft of the screw machine, and to a cleaning system comprising such a housing cleaning device and/or such a shaft cleaning device. The invention is further directed to a method for cleaning a screw machine.

From DE 44 17 357 A1 a method and a device for cleaning a screw machine are known. Cleaning is carried out by passing cleaning fluid through the screw machine, wherein in particular connections for supplying the cleaning fluid are provided in a housing of the screw machine. Such a device requires complex design work on the screw machine, is maintenance-intensive and does not always guarantee the required cleaning quality.

The invention is based on an object of providing an improved housing cleaning device for cleaning a housing of a screw machine, which is particularly easy to maintain and ensures a high cleaning quality.

This object is achieved by a housing cleaning device for cleaning a housing of a screw machine, having a support unit displaceable relative to the housing, and at least one housing cleaning unit attached to the support unit for cleaning an inner wall of the housing, wherein the at least one housing cleaning unit is reversibly insertable into the housing. According to the invention, it has been recognized that the housing cleaning device with the support unit and the housing cleaning unit arranged thereon must be designed such that the at least one housing cleaning unit can be inserted reversibly into the housing of the screw machine in order to ensure a high cleaning quality in the region of the housing of the screw machine incurring low maintenance effort, in particular without constructive modification measures. For cleaning the housing, the at least one treatment element shaft of the screw machine is removed from the housing. The screw machine may be designed as a single-shaft screw machine. Preferably, the screw machine is a multi-shaft screw machine, in particular a twin-shaft screw machine. Preferably, all of the treatment element shafts are removed from the housing for cleaning the housing. Insertability into the housing is understood to mean insertability into an interior space of the housing, in particular into a treatment space of the housing. Preferably, the support unit and/or the at least one housing cleaning unit are insertable into the housing along at least 25%, in particular at least 50%, in particular 75%, of a longitudinal extension of the interior space, in particular of the treatment space. For this purpose, a dimension of the support unit and/or of the at least one housing cleaning unit, in particular in radial direction to a longitudinal axis of the support unit, is smaller than a dimension of the interior space. A longitudinal extension of the support unit, is preferably at least 25%, in particular at least 50%, in particular at least 75%, in particular at least 100% of a length of the interior space. Advantageously, this ensures that the inner wall of the housing can be reliably cleaned over its entire length.

According to one aspect of the invention, the housing cleaning unit is displaceable relative to the housing along and/or transversely to a longitudinal direction of the housing, particularly when cleaning the housing. Cleaning of the housing can thus be performed in a particularly flexible and safe manner.

The support unit can be designed rigidly, in particular as a rigid rod, or flexibly, in particular as a chain and/or a rope. The support unit can be designed as a telescopic rod for easy insertion into the housing and/or for displacement in the housing. Cleaning of the housing can thus be carried out even when only little installation space is available.

According to one aspect of the invention, the housing cleaning device is designed to introduce at least one cleaning medium into the housing. The at least one cleaning medium may comprise liquid components, in particular water and/or solvents and/or acidic cleaning media and/or alkaline cleaning media, and/or solid components, in particular cleaning granules, in particular cleaning sand and/or ceramic granules and/or dry ice, and/or suspensions of the solid and liquid components, and/or compressed air, in particular hot air, and/or steam. In particular, the housing cleaning device can be designed to introduce different cleaning media into the housing simultaneously or one after the other in time. The housing cleaning device can be designed for wet cleaning with liquid cleaning media. The housing cleaning device can be designed to introduce the cleaning medium into the housing at an adjustable temperature and/or pressure. The housing cleaning device can also be designed for, in particular, exclusively dry cleaning, in particular with com-pressed air. Preferably, the housing cleaning device is designed for cleaning the housing in a plurality of timely consecutive steps. Preferably, the dry cleaning is performed in the last of the consecutive cleaning steps in order to avoid corrosion of the housing. In particular, the last cleaning step may comprise the application of an anti-corrosion agent. In particular, drying the housing with the compressed air ensures that corrosion is reliably avoided.

Preferably, the housing cleaning device comprises at least one inflow valve and/or at least one outflow valve for controlling an inflow and/or an outflow of the cleaning medium. The cleaning process can thus be controlled in a particularly flexible manner.

The housing comprises a feed opening for feeding the medium to be conveyed. Further, the housing comprises a discharge opening for discharging the medium to be conveyed. According to one aspect of the invention, the housing cleaning device comprises a closing unit for closing the discharge opening. Preferably, the closing unit can be attached to the housing in a sealing manner. The closing unit may have a discharge line for conducting the at least one cleaning medium out of the housing. Further, the closing unit may have a support unit feedthrough for passing the support unit therethrough. In the region of the support unit feedthrough, the support unit may penetrate the closing unit. Preferably, the closing unit has a feedthrough seal for sealing with respect to the support unit. The closing unit may have a feedthrough bearing for axially and/or rotationally mounting the support unit. By arranging the closing unit on the housing, the latter can be sealed to the greatest possible extent during the cleaning procedure. The support unit and/or the at least one housing cleaning unit can be displaced freely to the greatest possible extent, at a defined distance from the housing, due to the support unit feedthrough.

According to one aspect of the invention, the housing cleaning device has a housing drive means. The housing drive means may be attached to the support unit, in particular in a reversible manner. The housing drive means is preferably configured as to rotationally and/or translationally displace the support unit and/or the at least one housing cleaning unit relative to the housing, in particular along the longitudinal extension of the housing. The housing drive means may be integrated into the closing unit, in particular into the feedthrough bearing. The housing drive means enables an automation of the cleaning of the housing.

According to one aspect of the invention, the at least one housing cleaning unit is designed for cleaning a gear lantern of the screw machine. Preferably, the at least one housing cleaning unit is fixedly arranged in the gear lantern or can be reversibly inserted into the gear lantern. Advantageously, this ensures that the gear lantern can also be reliably freed from contaminants.

The screw machine preferably has a feed hopper for feeding, in particular for metering, a medium to be conveyed by means of the screw machine. The medium can be, for example, a plastic medium, in particular in the form of granules. The housing cleaning device can have a hopper feeding device for feeding the cleaning medium via the feed hopper. The hopper feeding device can be supplied with the cleaning medium together with the at least one housing cleaning unit via a common supply device. In particular, the hopper feeding device and the at least one cleaning unit are in fluid-conducting connection with the same supply device. A feed hopper of the screw machine can thus be cleaned particularly reliably and efficiently.

A housing cleaning device in which the at least one housing cleaning unit has at least one housing cleaning nozzle for discharging at least one cleaning medium ensures a particularly reliable cleaning of the housing. Preferably, more than one cleaning medium can be discharged via the at least one housing cleaning nozzle. Preferably, the at least one housing cleaning unit comprises at least two housing cleaning nozzles which have different nozzle shapes. The nozzle shape of the at least one housing cleaning nozzle can be round, in particular circular or slot-shaped.

The support unit may have an integrated line for conducting the at least one cleaning medium. For this purpose, the support unit can be designed as a hollow rod and/or as a tube. The at least one housing cleaning nozzle may be in fluid-conducting connection with the support unit. The housing cleaning device is thus particularly easy to handle.

A housing cleaning device in which the at least one housing cleaning nozzle is rotatably mounted relative to the support unit ensures particularly intensive cleaning of the housing. The at least one housing cleaning nozzle is attached to the support unit preferably to be driven in rotation. The at least one housing cleaning nozzle may be motor-driven. Alternatively, the at least one housing cleaning nozzle may be rotationally drivable by the flow of the cleaning medium, in particular by the discharge of the cleaning medium. For this purpose, the at least one housing cleaning nozzle can be designed such that, when the cleaning medium is discharged, a torque is provided about a housing nozzle axis, about which the at least one housing cleaning nozzle is rotatably mounted.

A housing cleaning device in which the at least one housing cleaning unit has at least one housing contact cleaning element, connected with the support unit, for contact cleaning of the housing ensures an improved cleaning of the housing. The housing contact cleaning element can be designed as a cleaning brush and/or as a cleaning sponge and/or as a cleaning chain for knocking off stubborn soiling and/or as a cleaning sieve for sieving out contaminants from the cleaning medium and/or as a cleaning cloth and/or as a pull-off lip, in particular for pulling moist surfaces dry. The housing contact cleaning element designed as a cleaning brush can be designed as a solid brush and/or as a spiral-shaped helical brush, in particular with a continuous brush comb and/or with brush bundles spaced apart from one another. Preferably, the housing contact cleaning element designed as a cleaning brush is configured to be similar to the screw elements of the treatment element shaft. Preferably, the cleaning brushes of mutually spaced support units are designed such that they contact each other in a wiping manner during the cleaning procedure of the housing, in particular engage with one another. Preferably, the housing contact cleaning element is designed such that the cleaning brushes can be combined with one another, depending on the degree of contamination of the housing, in particular can be connected with the support unit in a modular and/or reversible manner. For example, a comparatively soft cleaning brush can be used for a conveying zone of the housing, whereas a harder cleaning brush can be used for a melting zone of the housing. For simultaneous cleaning of both the conveying zone and the melting zone, the softer and the harder brush can be attached to the support unit at a distance from each other. The at least one housing contact cleaning element may have a plastic material and/or a metal, in particular a non-ferrous metal, in particular brass and/or copper.

According to one aspect of the invention, the at least one housing contact cleaning element displaceable, in particular rotatable, relative to the at least one support unit. For example, the at least one housing contact cleaning element may be configured as a rotatable cleaning roller.

In accordance with another aspect of the invention, the housing cleaning device has at least two housing contact cleaning elements. These may be rotatably mounted about axes that are spaced apart from one another in the transverse direction. Preferably, the at least two housing contact cleaning elements are designed as to mesh tightly with one another and/or as to penetrate one another. Advantageously, this ensures that the at least two housing contact cleaning elements clean each other.

According to one aspect of the invention, the housing cleaning device has at least one housing cleaning unit configured as a housing cleaning nozzle and at least one housing cleaning unit con-figured as a housing contact cleaning element. Preferably, the at least one housing cleaning nozzle is disposed along the longitudinal axis at the same height as the at least one housing contact cleaning element.

A housing cleaning device in which the support unit has a coupling portion for the connection with a shaft drive of the screw machine can be manufactured in a particularly inexpensive manner. The coupling portion preferably is designed for the torque-transmitting connection to a lantern coupling in the transmission lantern. The coupling portion may be formed as a splined shaft connection. The housing drive means may be entirely formed by the shaft drive of the screw machine. Additional components for displacing the support unit and/or the at least one housing cleaning unit relative to the housing may be saved.

According to one aspect of the invention, the coupling portion and/or the lantern coupling are configured as to provide automatic detection of the support unit connected thereto and/or the specific design of the housing cleaning device. This enables the screw machine, in particular a control device of the screw machine, to automatically detect the connection of the housing cleaning device. A cleaning program can be automatically selected according to the specific design of the housing cleaning device. Operating parameters of the screw machine may be preset correspondingly, in particular limited for safety reasons.

A housing cleaning device in which the support unit is designed as to be rotatably mounted relative to the housing ensures particularly reliable and intensive cleaning of the housing. For driving the support unit in rotation, the latter can be connected to the shaft drive and/or the housing drive means in a torque-transmitting manner, as described above. Alternatively, the torque required for rotation can be provided by discharging the cleaning medium via the at least one housing cleaning nozzle.

A housing cleaning device comprising at least one support coupling for reversibly connecting the at least one housing cleaning unit with the support unit can be applied in a particularly flexible manner and can be maintained easily. Due to the fact that the at least one housing cleaning unit can be reversibly attached to the support unit by means of the at least one support coupling, the at least one housing cleaning unit can be adapted according to the requirements of the respective cleaning process. For example, the at least one housing cleaning unit can be selected such that its dimensions safely ensure easy insertion into the housing and reliable cleaning of the housing. In particular, the at least one housing contact cleaning element connected to the support unit may be configured as to reliably engage with the housing. Preferably, the at least one support coupling can be released without tools. Preferably, the at least one support coupling comprises a mechanical connection and/or at least one fluid-conducting connection for conducting the at least one cleaning medium.

A housing cleaning device comprising a guide unit for axially guiding the support unit on the housing can be displaced particularly easily and safely in the housing. By forming the housing cleaning device with the guide unit, the housing cleaning device can be reliably prevented from hitting the housing. The guide unit may be of contacting or non-contacting design. According to one aspect of the invention, the guide unit may be formed by the housing contact cleaning element, in particular as a cleaning brush. The housing contact cleaning element, in particular the cleaning brush, may be configured for, in particular concentrically, guiding the housing cleaning device in the housing. The contacting guide unit can have a guide body for mechanically guiding the housing cleaning device, in particular the support unit, in the housing. The guide body preferably has a central recess through which the support unit passes. The guide body can be configured in a disc-shaped and/or star-shaped manner. Preferably, the guide body has drainage recesses through which the at least one cleaning medium can flow off along the longitudinal axis.

The guide unit, which is designed to be contact-free, ensures that the support unit is guided by discharging the at least one cleaning medium. For this purpose, the guide unit may have guide nozzles for discharging the cleaning medium. The guide nozzles can be designed as housing cleaning nozzles. Due to the contact-free guidance of the support unit in the housing, the mechanical stress on the inner wall is reduced. Damage to the housing can be reliably prevented.

A housing cleaning device in which the support unit is designed as to be modular, and for this purpose has at least two support modules which are reversibly connectable with one another along a longitudinal axis of the support unit can be operated particularly flexibly and cost-efficiently. The reversibly interconnectable support modules can have different dimensions. In particular, the support modules can have different housing cleaning units. The possibility of replacing individual support modules enables the housing cleaning device to be adapted to the respective cleaning requirements, as well as the replacement of individual support modules due to wear.

In accordance with one aspect of the invention, the support unit may have at least one branch support module branching from a main support module.

A housing cleaning device in which the support unit has an adjustment element which is designed such that the at least one housing cleaning unit is arrangeable at the support unit, at an adjustable distance transversely to a longitudinal axis of the support unit is particularly flexible in use. The housing cleaning device with the housing cleaning unit arranged at a distance transversely to the longitudinal axis, wherein the distance between the longitudinal axis and the housing cleaning unit is adjustable, can be flexibly applied for housings with different inner diameters. Preferably, at least two housing cleaning units, in particular diametrically opposing one another, can be arranged on the support unit at an adjustable distance transversely to the longitudinal axis. Advantageously, this allows several housing bores of a screw machine to be cleaned simultaneously. The at least two housing cleaning units can preferably be arranged at the support unit such that a distance between them corresponds to a distance between the central longitudinal axes of the housing bores. The housing cleaning device is thus designed for efficient cleaning of multi-shaft screw machines.

According to one aspect of the invention, the housing cleaning device is configured for non-rotationally symmetrical cleaning of the housing. This enables cleaning, in particular of a plurality of housing bores, of a multi-shaft screw machine in an efficient manner.

A housing cleaning device in which the at least one housing cleaning unit is designed as to convey contaminants along a longitudinal axis of the support unit ensures the reliable transport of the at least one cleaning medium in the housing. For conveying the contaminants along the longitudinal axis, the at least one housing cleaning nozzle can have a spray direction oriented at least partially in the direction of the longitudinal axis, in particular in the direction of an outflow, in particular of the discharge opening. The at least one housing cleaning nozzle can also be oriented opposite to a conveying direction of the screw machine.

Due to this, contaminants can be efficiently soaked. At least one housing cleaning nozzle is preferably oriented transversely to a longitudinal extension of the support unit, in order to reliably loosen contaminants from the housing. According to one further aspect of the invention, the at least one housing contact cleaning element, in particular the cleaning brush and/or the pull-off lip, is configured in a spiral-shaped manner, in particular with a conveying pitch. The spiral-shaped housing contact cleaning element preferably has at least one, in particular at least two, in particular at least three, threads. When the at least one housing contact cleaning element is rotated, the cleaning medium can thereby be conveyed, in particular in the direction of an outflow, in particular of the discharge opening.

Preferably, the at least one housing cleaning unit, in particular the housing contact cleaning element and/or the housing cleaning nozzle, is designed for displacement, in particular linear dis-placement and/or rotation, of the housing cleaning device relative to the housing of the screw machine. For example, the housing cleaning nozzle may be oriented such that the fluid mass flow applied through said housing cleaning nozzle causes an impulse to displace the housing cleaning device relative to the housing. The housing contact cleaning element may be configured such that the displacement of the housing cleaning device by means of the housing drive means causes a displacement of the housing cleaning device relative to the housing, due to the contact of the housing contact cleaning element with the housing. For example, for this purpose, the housing cleaning unit may comprise obliquely oriented cleaning brushes and/or housing cleaning nozzles oriented in the displacement direction.

A housing cleaning device comprising a housing control device for automated controlling of a displacement of the support unit relative to the housing and/or of a mass flow of at least one cleaning medium introduced into the housing can be operated particularly economically. The housing control device may be in signal communication with the at least one inflow valve and the at least one outflow valve, for controlling the mass flow of the cleaning medium discharged via the at least one housing cleaning nozzle. Further, the housing control device may be in signal communication with the housing drive means, for automated displacement of the support unit relative to the housing. The housing control device may also be in signal communication with a drive of the at least one housing contact cleaning element and/or a pump for conveying the cleaning medium. The cleaning of the housing can thus be carried out in a particularly cost- and time-efficient manner.

The invention is further based on an object of creating a shaft cleaning device for cleaning at least one treatment element shaft of a screw machine, which can be used for existing screw machines and ensures the cleaning of the treatment element shaft in a particularly reliable manner and is easy to maintain.

This object is achieved by a shaft cleaning device for cleaning at least one treatment element shaft of a screw machine, having a cleaning chamber in which the at least one treatment element shaft is arrangeable, and at least one shaft cleaning unit arranged in the cleaning chamber. The advantages of the shaft cleaning device according to the invention correspond to the advantages of the housing cleaning device described. In particular, the at least one shaft cleaning unit can be further developed with the features of the at least one housing cleaning unit.

Preferably, the cleaning chamber has at least one, in particular at least two, in particular at least three, in particular at least four cleaning portions. Preferably, the cleaning portions are separated from each other in a fluid-tight or liquid-tight manner by chamber seals. The chamber seals can be designed as sealing curtains.

According to one further aspect of the invention, the shaft cleaning device may be configured to receive the at least one treatment element shaft without displacement relative to the cleaning chamber. Preferably, the at least one shaft cleaning unit is configured such that it is displaceable relative to the at least one treatment element shaft and/or to the cleaning chamber. For example, the at least one shaft cleaning unit can be designed as to be displaceable along the longitudinal axis and/or about the chamber longitudinal axis, in particular about the treatment element shaft, in particular in a circular and/or spiral manner. The cleaning of the treatment element shaft can thus be carried out particularly intensively and reliably.

According to one aspect of the invention, the cleaning chamber has at least one viewing window. By means of the viewing window, the cleaning state of the treatment element shaft can be monitored. The cleaning chamber may have a, in particular sealed, hand access for manual cleaning by a user. For this purpose, the shaft cleaning device may have a shaft cleaning unit that can be manually displaced relative to the at least one treatment element shaft.

A shaft cleaning device in which the at least one shaft cleaning unit has at least one shaft cleaning nozzle for discharging at least one cleaning medium ensures a particularly thorough cleaning of the at least one treatment element shaft. Preferably, the at least one shaft cleaning nozzle can be further developed with the features of the at least one housing cleaning nozzle.

A shaft cleaning device comprising shaft drive means for displacing the treatment element shaft relative to the at least one shaft cleaning unit can be operated particularly economically. The shaft drive device can be designed for translational and/or rotational displacement of the at least one treatment element shaft relative to the cleaning chamber. For example, the treatment element shaft can be displaceable by means of the shaft drive device in a purely rotational manner, in particular about a chamber longitudinal axis of the cleaning chamber. Alternatively, the at least one treatment element shaft can be translationally displaced relative to the cleaning chamber by means of the shaft drive device. In particular, the shaft drive device can be configured as to move the treatment element shaft through the cleaning chamber, in particular the plurality of cleaning portions, during the cleaning procedure. Due to the fact that the shaft cleaning device is formed with a shaft drive device, the cleaning of the at least one treatment element shaft can be automated.

A shaft cleaning device comprising at least one wet cleaning portion and/or at least one dry cleaning portion ensures a particularly thorough cleaning of the at least one treatment element shaft. Stress on the treatment element shaft due to moisture-related corrosion is reliably prevented. In the at least one wet cleaning portion, liquid cleaning medium is applied to the treatment element shaft. In the at least one dry cleaning portion, the treatment element shaft is cleaned without the use of liquid cleaning media. In particular, the at least one dry cleaning portion is configured as to dry the treatment element shaft. For this purpose, the shaft cleaning device may have at least one drying blower in the region of the dry cleaning portion.

The at least one shaft cleaning unit may have at least one shaft contact cleaning element. The at least one shaft contact cleaning element may be further developed by the features of the at least one housing contact cleaning element. Preferably, the at least one shaft contact cleaning element can be driven in rotation. In particular, the at least one shaft contact cleaning element may be configured as a cleaning brush, in particular one that tightly meshes with the at least one treatment element shaft. According to one aspect of the invention, the at least one shaft cleaning unit has the at least one shaft contact cleaning unit in the form of a cleaning brush, in the dry cleaning portion.

According to one further aspect of the invention, the shaft cleaning device is configured as to discharge exclusively clear water in at least one of the cleaning portions. The shaft cleaning device may further be configured as to discharge cleaning medium containing alkali and/or acid and/or cleaning granules in at least one of the cleaning portions. Preferably, the wet cleaning portion comprises, in particular sequentially, a soaking portion and/or a cleaning portion and/or a clear rinsing portion. The shaft cleaning device can also be designed for complete dry cleaning. For this purpose, the shaft cleaning device can be designed for discharging gaseous cleaning medium in particular provided with cleaning granules, and/or have, in particular exclusively, the at least one shaft contact cleaning element for contact cleaning of the treatment element shaft.

A shaft cleaning device in which the cleaning chamber is designed as to be modular and for this purpose has at least two chamber modules which are reversibly connectable to one another along a chamber longitudinal axis of the cleaning chamber can be operated particularly flexibly and economically. Preferably, each of the at least two reversibly interconnectable chamber modules is de-signed as to form at least one, in particular at least two, cleaning portions. Advantageously, this ensures that the cleaning chamber can be flexibly adapted according to the length of the at least one treatment element shaft. Furthermore, different cleaning functions can be combined with each other. Individual chamber modules can be replaced for easy maintenance.

The invention is further based on an object of creating a cleaning system for a screw machine that can be used flexibly for different screw machines and ensures particularly thorough cleaning of the screw machine.

This object is achieved by a cleaning system with a supply device for providing at least one cleaning medium and a housing cleaning device and/or a shaft cleaning device. The advantages of the cleaning system according to the invention correspond to the advantages of the housing cleaning device and the shaft cleaning device already described. Due to the design of the cleaning system with the supply device, the provision of the at least one cleaning medium can be reliably ensured. Interface problems can be reliably prevented.

According to one aspect of the invention, the supply device is configured as to provide at least two cleaning media. Preferably, at least two, in particular at least three, in particular at least four, of the cleaning media differ in terms of composition. Furthermore, the supply device may be configured as to control a pressure and/or a temperature of the at least one cleaning medium. In particular, the supply device can be designed as to provide at least one of the cleaning media described above.

Preferably, the supply device is designed as a circuit supply device. The circuit supply device is characterized in that the at least one cleaning medium is supplied cyclically to the housing cleaning device and/or the shaft cleaning device. Such a supply device can be operated in a particularly economical and environmentally friendly manner.

The supply device can be designed for mechanical and/or chemical and/or biological processing of the cleaning medium. In particular, the supply device for processing the cleaning medium can have a cleaning unit, in particular a filter and/or an oil separator and/or a cleaning element for chemical cleaning. This allows contaminants to be removed from the at least one cleaning medium.